- From: Sandro Hawke <sandro@w3.org>
- Date: Wed, 25 Apr 2012 10:08:55 -0400
- To: public-rdf-wg <public-rdf-wg@w3.org>
If we're going to talk about graphs today, maybe we can do it in a
series of decisions. There's not enough notice to make these binding,
of course, but maybe we can get a sense of how close we are to
consensus.
If we can't even get consensus on a few of these, these I think we
should stop working on graph semantics in this WG. I hope we're very
close to consensus on all of these, except maybe the last, which I could
see continuing as an open issue well into CR.
I've erred on the side of brevity here.
-- Sandro
====================================
1. The default graph is asserted
"{<a> <b> <c>}" entails turtle("<a> <b> <c>")
2. Named graphs are not asserted
"<u> {<a> <b> <c>}" does not entail turtle("<a> <b> <c>")
3. Named graphs are opaque
"<u> {<a> <b> <c>}" does not entail "<u> {<a> <b> _:x}"
4. Graph labels denote just like in RDF
"{<u1> owl:sameAs <u2>} <u1> {<a> <b> <c>}"
owl-entails
"<u2> {<a> <b> <c>}"
5. Blank nodes labels have file scope
See SPARQL queries in
http://www.w3.org/2011/rdf-wg/wiki/Graphs_Design_6.1#Blank_Nodes
or Skolemization example in
http://lists.w3.org/Archives/Public/public-rdf-wg/2012Apr/0132.html
6. In trig, @union can be used in place of the default graph
"@union <u> {<a> <b> <c>}" entails turtle "<a> <b> <c>"
7. Datasets only say which triples are known to be in a named graph,
not which triples are *not* in that named graph.
The merge of "<u> {<a> <b> <c>}" and "<u> {<a> <b> <d>}" is
"<u> {<a> <b> <c>,<d>}".
Also "<u> {<a> <b> <c>,<d>}" entails "<u> {<a> <b> <c>}".
Received on Wednesday, 25 April 2012 14:09:08 UTC